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Programmatically scroll a UIScrollView

I have a UIScrollView which has several views. When a user flicks their finger, the view scrolls to the right or left depending on the direction of the finger flick. Basically my code works in a way similar to the iPhone photo app. Now, is there a way that I can programmatically do the same thing so that I end up with a slideshow that runs on its own with a click of a button and a configurable pause between each scroll?

How do you really do slideshows with UIScrollView?


C
Community

You can scroll to some point in a scroll view with one of the following statements in Objective-C

[scrollView setContentOffset:CGPointMake(x, y) animated:YES];

or Swift

scrollView.setContentOffset(CGPoint(x: x, y: y), animated: true)

See the guide "Scrolling the Scroll View Content" from Apple as well.

To do slideshows with UIScrollView, you arrange all images in the scroll view, set up a repeated timer, then -setContentOffset:animated: when the timer fires.

But a more efficient approach is to use 2 image views and swap them using transitions or simply switching places when the timer fires. See iPhone Image slideshow for details.


Cool. Yes, I did find that setContentOffset works but really wanted this to happen in animated way. 'animated:YES' did the trick.
Just complementing the answer, to move horizontally to the next "page" in UIScrollView (assuming you are coding for iPhone), for the x parameter use (myScrollView.contentOffset.x +320).
@niraj thanks dude...in (myScrollView.contentOffset.x +320) lies the key!
Correct me if I'm wrong, but UIScrollView's contentOffset: will offset the contentSize as well, which may not be desirable. To only scroll, you may want to use scrollRectToVisible:.
Do no use C helper functions like CGPointMake in Swift. Simply build a Swift struct directly: CGPoint(x: 0, y: 44)
J
Jon Schneider

If you want control over the duration and style of the animation, you can do:

[UIView animateWithDuration:2.0f delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
    scrollView.contentOffset = CGPointMake(x, y);
} completion:NULL];

Adjust the duration (2.0f) and options (UIViewAnimationOptionCurveLinear) to taste!


v
vol

I'm amazed that this topic is 9 years old and the actual straightforward answer is not here!

What you're looking for is scrollRectToVisible(_:animated:).

Example:

extension SignUpView: UITextFieldDelegate {
    func textFieldDidBeginEditing(_ textField: UITextField) {
        scrollView.scrollRectToVisible(textField.frame, animated: true)
    }
}

What it does is exactly what you need, and it's far better than hacky contentOffset

This method scrolls the content view so that the area defined by rect is just visible inside the scroll view. If the area is already visible, the method does nothing.

From: https://developer.apple.com/documentation/uikit/uiscrollview/1619439-scrollrecttovisible


good solution, but contentOffset gives more control over where exactly you want to scroll
L
Luke

Another way is

scrollView.contentOffset = CGPointMake(x,y);

This is exactly the same as the accepted answer. And CGPoint should be CGPointMake.
I like simple answers like this one.
Actually, this is not the same as the accepted answer. The accepted answer has an option of animated, which some apps might want to have set to YES.
M
Michael

With Animation in Swift

scrollView.setContentOffset(CGPointMake(x, y), animated: true)

O
Olcay Ertaş

Swift 3

let point = CGPoint(x: 0, y: 200) // 200 or any value you like.
scrollView.contentOffset = point

C
CoderPug
scrollView.setContentOffset(CGPoint(x: y, y: x), animated: true)

P
P.J.Radadiya
[Scrollview setContentOffset:CGPointMake(x, y) animated:YES];

u
user1781290
- (void)viewDidLoad
{
    [super viewDidLoad];
    board=[[UIView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.height, 80)];
    board.backgroundColor=[UIColor greenColor];
    [self.view addSubview:board];
    // Do any additional setup after loading the view.
}


-(void)viewDidLayoutSubviews
{


    NSString *str=@"ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    index=1;
    for (int i=0; i<20; i++)
    {
        UILabel *lbl=[[UILabel alloc]initWithFrame:CGRectMake(-50, 15, 50, 50)];
        lbl.tag=i+1;
        lbl.text=[NSString stringWithFormat:@"%c",[str characterAtIndex:arc4random()%str.length]];
        lbl.textColor=[UIColor darkGrayColor];
        lbl.textAlignment=NSTextAlignmentCenter;
        lbl.font=[UIFont systemFontOfSize:40];
        lbl.layer.borderWidth=1;
        lbl.layer.borderColor=[UIColor blackColor].CGColor;
        [board addSubview:lbl];
    }

    [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(CallAnimation) userInfo:nil repeats:YES];

    NSLog(@"%d",[board subviews].count);
}


-(void)CallAnimation
{

    if (index>20) {
        index=1;
    }
    UIView *aView=[board viewWithTag:index];
    [self doAnimation:aView];
    index++;
    NSLog(@"%d",index);
}

-(void)doAnimation:(UIView*)aView
{
    [UIView animateWithDuration:10 delay:0 options:UIViewAnimationOptionCurveLinear  animations:^{
        aView.frame=CGRectMake(self.view.frame.size.height, 15, 50, 50);
    }
                     completion:^(BOOL isDone)
     {
         if (isDone) {
             //do Somthing
                        aView.frame=CGRectMake(-50, 15, 50, 50);
         }
     }];
}

Please consider adding some text to your answer, not only pure code
M
Mussa Charles

Here is another use case which worked well for me.

User tap a button/cell. Scroll to a position just enough to make a target view visible.

Code: Swift 5.3

// Assuming you have a view named "targeView"
scrollView.scroll(to: CGPoint(x:targeView.frame.minX, y:targeView.frame.minY), animated: true)

As you can guess if you want to scroll to make a bottom part of your target view visible then use maxX and minY.